我有两种情况。一种有效,一种无效。第一个(有效的)包含一个直接位于表单上的滚动框,当按下按钮时,它会执行以下代码:
procedure TForm1.Button2Click(Sender: TObject);
begin
DrawPanel;
end;
procedure TForm1.DrawPanel;
begin
BuildPanel; //Resides on a seperate unit code pasted below
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
unit Unit3;
interface
uses ExtCtrls;
Var
TestPanel : Tpanel;
Procedure BuildPanel;
implementation
procedure BuildPanel;
begin
TestPanel := TPanel.Create(Nil);
end;
end.
代码是相同的,除了在第二种情况下的细微差别。滚动框位于添加到模板调色板的框架上,然后下拉到表单上。按钮点击调用:
procedure TForm1.Button1Click(Sender: TObject);
begin
TestFrame.DrawPanel;
end;
procedure TTestFrame.DrawPanel;
begin
BuildPanel; //Still points to the unit3 code above
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
但是,在运行时触发时,面板不会显示在框架上的滚动框中。我不确定为什么,有人可以帮忙吗?我希望我的问题足够具体,如果有任何不清楚的地方,请告诉我。提前致谢。
这是按顺序排列的所有代码.....希望它更清楚:
//This is the form
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls, Unit2, Unit3;
type
TForm1 = class(TForm)
Button1: TButton;
TTestFrame1: TTestFrame;
ScrollBox1: TScrollBox;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
TestFrame: TTestFrame;
Procedure DrawPanel;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
begin
TestFrame.DrawPanel;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
DrawPanel;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
TestFrame.Free;
end;
procedure TForm1.FormShow(Sender: TObject);
begin
TestFrame := TTestFrame.Create(Form1);
end;
procedure TForm1.DrawPanel;
begin
BuildPanel;
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
end.
//This is the frame
unit Unit2;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Unit3;
type
TTestFrame = class(TFrame)
ScrollBox1: TScrollBox;
private
{ Private declarations }
public
{ Public declarations }
Procedure DrawPanel;
end;
implementation
{$R *.dfm}
{ TTestFrame }
procedure TTestFrame.DrawPanel;
begin
BuildPanel;
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
end.
//This is the unit that mocks my data structure
//In reality it creates an Array of Tpanel that is part of a class.
unit Unit3;
interface
uses ExtCtrls;
Var
TestPanel : Tpanel;
Procedure BuildPanel;
implementation
procedure BuildPanel;
begin
TestPanel := TPanel.Create(Nil);
end;
end.